<template>
	<view class="u-wrap">
		<up-navbar placeholder title="筛选" @leftClick="back" rightText="确定" @rightClick="ok" :autoBack="true"></up-navbar>
		<view class="u-menu-wrap">
			<scroll-view scroll-y scroll-with-animation class="u-tab-view menu-scroll-view" :scroll-top="scrollTop" :scroll-into-view="itemId">
				<view v-for="(item, index) in tabbar" :key="index" class="u-tab-item" :class="[current == index ? 'u-tab-item-active' : '']" @tap.stop="swichMenu(index)">
					<text class="u-line-1" style="margin-left: 10px">{{ item.industryName }}</text>
				</view>
			</scroll-view>
			<scroll-view :scroll-top="scrollRightTop" scroll-y scroll-with-animation class="right-box" @scroll="rightScroll">
				<view class="page-view">
					<view class="class-item" :id="'item' + index" v-for="(item, index) in tabbar" :key="index">
						<view class="item-title">
							<text>{{ item.industryName }}</text>
						</view>
						<view class="item-container">
							<view
								class="thumb-box"
								:class="{ highlight: isSelected(item1.key, item.industryName) }"
								v-for="(item1, index1) in item.positions"
								:key="index1"
								@click="selectItem(item1.key, item.industryName)"
							>
								<view>{{ item1.positionName }}</view>
							</view>
						</view>
					</view>
				</view>
			</scroll-view>
		</view>
	</view>
</template>
<script>
import classifyData from '@/common/classify.data.js';
export default {
	data() {
		return {
			scrollTop: 0, //tab标题的滚动条位置
			oldScrollTop: 0,
			current: 0, // 预设当前项的值
			menuHeight: 0, // 左边菜单的高度
			menuItemHeight: 0, // 左边菜单item的高度
			itemId: '', // 栏目右边scroll-view用于滚动的id
			tabbar: [],
			menuItemPos: [],
			arr: [],
			scrollRightTop: 0, // 右边栏目scroll-view的滚动条高度
			timer: null, // 定时器
			keyword: '',
			selectedItems: {}
		};
	},
	onReady() {
		this.$api.getindustry().then((res) => {
			this.tabbar = classifyData;
			res.data.forEach((data) => {
				let existingIndustry = this.tabbar.find((item) => item.industryName === data.industryName);
				if (existingIndustry) {
					existingIndustry.positions = data.positions.map((position) => ({
						positionName: position.positionName,
						key: position.positionId
					}));
				} else {
					this.tabbar.push({
						industryName: data.industryName,
						positions: data.positions.map((position) => ({
							positionName: position.positionName,
							key: position.positionId
						}))
					});
				}
			});
			this.restoreSelections();
		});
		this.getMenuItemTop();
	},
	methods: {
		// 返回
		back() {
			uni.navigateTo({
				url: '/pages/view/view'
			});
		},
		// 点击左边的栏目切换
		async swichMenu(index) {
			if (this.arr.length == 0) {
				await this.getMenuItemTop();
			}
			if (index == this.current) return;
			this.scrollRightTop = this.oldScrollTop;
			this.$nextTick(function () {
				this.scrollRightTop = this.arr[index];
				this.current = index;
				this.leftMenuStatus(index);
			});
		},
		// 获取一个目标元素的高度
		getElRect(elClass, dataVal) {
			new Promise((resolve, reject) => {
				const query = uni.createSelectorQuery().in(this);
				query
					.select('.' + elClass)
					.fields(
						{
							size: true
						},
						(res) => {
							// 如果节点尚未生成，res值为null，循环调用执行
							if (!res) {
								setTimeout(() => {
									this.getElRect(elClass);
								}, 10);
								return;
							}
							this[dataVal] = res.height;
							resolve();
						}
					)
					.exec();
			});
		},
		// 观测元素相交状态
		async observer() {
			this.tabbar.map((val, index) => {
				let observer = uni.createIntersectionObserver(this);
				// 检测右边scroll-view的id为itemxx的元素与right-box的相交状态
				// 如果跟.right-box底部相交，就动态设置左边栏目的活动状态
				observer
					.relativeTo('.right-box', {
						top: 0
					})
					.observe('#item' + index, (res) => {
						if (res.intersectionRatio > 0) {
							let id = res.id.substring(4);
							this.leftMenuStatus(id);
						}
					});
			});
		},
		// 设置左边菜单的滚动状态
		async leftMenuStatus(index) {
			this.current = index;
			// 如果为0，意味着尚未初始化
			if (this.menuHeight == 0 || this.menuItemHeight == 0) {
				await this.getElRect('menu-scroll-view', 'menuHeight');
				await this.getElRect('u-tab-item', 'menuItemHeight');
			}
			// 将菜单活动item垂直居中
			this.scrollTop = index * this.menuItemHeight + this.menuItemHeight / 2 - this.menuHeight / 2;
		},
		// 获取右边菜单每个item到顶部的距离
		getMenuItemTop() {
			new Promise((resolve) => {
				let selectorQuery = uni.createSelectorQuery();
				selectorQuery
					.selectAll('.class-item')
					.boundingClientRect((rects) => {
						// 如果节点尚未生成，rects值为，循环调用执行
						if (!rects.length) {
							setTimeout(() => {
								this.getMenuItemTop();
							}, 10);
							return;
						}
						rects.forEach((rect) => {
							// 这里减去rects[0].top，是因为第一项顶部可能不是贴到导航栏(比如有个搜索框的情况)
							this.arr.push(rect.top - rects[0].top);
							resolve();
						});
					})
					.exec();
			});
		},
		// 右边菜单滚动
		async rightScroll(e) {
			this.oldScrollTop = e.detail.scrollTop;
			if (this.arr.length == 0) {
				await this.getMenuItemTop();
			}
			if (this.timer) return;
			if (!this.menuHeight) {
				await this.getElRect('menu-scroll-view', 'menuHeight');
			}
			setTimeout(() => {
				// 节流
				this.timer = null;
				// scrollHeight为右边菜单垂直中点位置
				let scrollHeight = e.detail.scrollTop + this.menuHeight / 4;
				for (let i = 0; i < this.arr.length; i++) {
					let height1 = this.arr[i];
					let height2 = this.arr[i + 1];
					// 如果不存在height2，意味着数据循环已经到了最后一个，设置左边菜单为最后一项即可
					if (!height2 || (scrollHeight >= height1 && scrollHeight < height2)) {
						this.leftMenuStatus(i);
						return;
					}
				}
			}, 10);
		},
		// 选择项目
		selectItem(key, industryName) {
			if (!this.selectedItems[industryName]) {
				this.selectedItems[industryName] = [];
			}
			if (key === 'all') {
				// 点击"全部"时，取消选中所有该大类字段
				this.selectedItems[industryName] = ['all'];
			} else {
				// 点击其它时，取消选中"全部"
				const allIndex = this.selectedItems[industryName].indexOf('all');
				if (allIndex !== -1) {
					this.selectedItems[industryName].splice(allIndex, 1);
				}
				const index = this.selectedItems[industryName].indexOf(key);
				if (index === -1) {
					this.selectedItems[industryName].push(key);
				} else {
					this.selectedItems[industryName].splice(index, 1);
				}
			}
		},
		// 已经选择处理
		isSelected(key, industryName) {
			return this.selectedItems[industryName] && this.selectedItems[industryName].includes(key);
		},
		// 恢复选中
		restoreSelections() {
			const storedSelections = uni.getStorageSync('filter');
			if (storedSelections) {
				this.selectedItems = storedSelections;
			}
			// 检查特定大类是否有选择，如果没有选择则默认选中"全部"
			const categoriesToSelectAll = ['学历', '薪资待遇', '经验要求', '公司规模'];
			categoriesToSelectAll.forEach((category) => {
				if (!this.selectedItems[category] || this.selectedItems[category].length === 0) {
					this.selectedItems[category] = ['all'];
				}
			});
		},
		// 确定
		ok() {
			uni.setStorageSync('filter', this.selectedItems);
			uni.navigateTo({
				url: '/pages/view/view'
			});
		}
	}
};
</script>

<style lang="scss" scoped>
.u-wrap {
	height: calc(100vh);
	/* #ifdef H5 */
	height: calc(100vh - var(--window-top));
	/* #endif */
	display: flex;
	flex-direction: column;
}

.u-search-box {
	padding: 18rpx 30rpx;
}

.u-menu-wrap {
	flex: 1;
	display: flex;
	overflow: hidden;
}

.u-search-inner {
	border-radius: 100rpx;
	display: flex;
	align-items: center;
	padding: 10rpx 16rpx;
}

.u-search-text {
	font-size: 26rpx;
	color: $u-tips-color;
	margin-left: 10rpx;
}

.u-tab-view {
	width: 250rpx;
	height: 100%;
	border-radius: 16rpx;
}

.u-tab-item {
	height: 110rpx;
	background: #f6f6f6;
	box-sizing: border-box;
	display: flex;
	align-items: center;
	justify-content: center;
	font-size: 25rpx;
	color: #444;
	font-weight: 400;
	line-height: 1;
}

.u-tab-item-active {
	position: relative;
	color: #000;
	font-size: 30rpx;
	font-weight: 600;
	background: #fff;
	border-radius: 16rpx;
}

.u-tab-item-active::before {
	content: '';
	position: absolute;
	border-left: 4px solid $u-primary;
	height: 32rpx;
	left: 0;
	top: 39rpx;
	border-radius: 16rpx;
}

.u-tab-view {
	height: 100%;
}

.right-box {
	background-color: rgb(250, 250, 250);
}

.page-view {
	padding: 20rpx;
	background-color: #f5f5f5;
}

.class-item {
	margin-bottom: 30rpx;
	background-color: #ffffff;
	padding: 20rpx;
	border-radius: 16rpx;
}

.item-title {
	font-size: 40rpx;
	font-weight: bold;
	color: #333;
	margin-bottom: 16rpx;
}

.item-container {
	display: flex;
	flex-wrap: wrap;
}

.thumb-box {
	padding: 12rpx 20rpx;
	background-color: #f6f6f6;
	border-radius: 16rpx;
	margin-right: 20rpx;
	margin-bottom: 20rpx;
	font-size: 30rpx;
	color: #666;
	border: 1px solid grey;
}

.highlight {
	border: 1px solid darkgreen;
	background-color: rgba(0, 100, 0, 0.2);
}
</style>
